Speedy1 is a SQL-database which is fully integrated into the application program. So you can build applications based on SQL-databases without the need for the user to install and maintain a database. The user does not even see that a database is used. Speedy1 is small, fast and simple to use. So linking the database to the application does not make the program much bigger.
If you have a small application which requires to systematically manage some data I think you should test Speedy1. At least it is a small download and can be installed quickly (and also de-installed - if ever needed).
You can get Speedy1 for Linux and Windows.
End-user does not need to install, administrate, maintain database
Programs without need for disk write access can be written
SQL-like interface (e.g. sub-selects, cursor-fetch, join, distinct, order by)
Multiple simultaneous connects to the database from different applications
Multiple databases are supported
Transactions are supported
High stability and efficient memory handling
Small number of source-code-lines (and small libraries)
"Secure" tables keep contents even if severe errors occur
Database must fit into virtual memory
Query optimisation has to be done manually
SQL-language not fully implemented (e.g. privileges, views, alter-table)
Some minor limitations to SQL-evaluation (e.g. only constant operands for BETWEEN and LIKE)
NULL-attributes are defined with DEFAULT-values rather than an explicit NULL-value